Functional-metabolic imaging of neuroblastoma.

Neuroblastoma is the third most common malignant solid tumor of childhood. It originates from primitive neural crest cells of the sympathetic nervous system. Many imaging procedures help guide therapy and predict outcomes. Anatomic imaging methods, such as CT and MRI, are most useful for evaluation of the primary tumor mass and nearby involved lymph nodes. Functional imaging tracers, such as [123I]MIBG, [18F]FDG, and [99mTc]MDP, are used to assess the extent of disease and to search for distant metastases. [123I]MIBG is the principal functional imaging tracer for the detection and monitoring of neuroblastoma. [18F]FDG PET/CT is an alternative that is valuable in tumors with poor or no MIBG-uptake. [99mTc]MDP bone scans may be useful to assess cortical bone metastases. This article will review the use of [123I]MIBG and other functional imaging agents for the management of patients with neuroblastoma.

The radiological approach to precocious puberty.

Precocious puberty is caused by a heterogeneous group of disorders, which range from idiopathic to malignant tumours. The radiologist's role is to help: (1) differentiate precocious puberty from pubertal variants; (2) identify the underlying cause of precocity if present; and (3) assess for effectiveness of treatment. This pictorial review discusses the types of precocious puberty and their underlying aetiologies, differentiates precocious puberty from pubertal variants and illustrates the appropriate imaging evaluation for the patient diagnosed with precocious puberty.

Complications of cancer therapy in children: a radiologist's guide.

As advances in cancer therapy improve the prognosis of patients with childhood malignancies, awareness of the consequences of treatment methods assumes increasing importance. All cancer treatment modalities are associated with toxic effects, and the spectrum of therapy-induced complications involves all organ systems. Radiologists have a pivotal role in detecting these sequelae, which can be categorized by the affected organ system and by whether they occur (a) at diagnosis or during initial therapy or (b) after the completion of treatment. The first group consists of oncologic emergencies, infectious complications, and irritant effects. Oncologic emergencies can be further categorized as space-occupying lesions (e.g., superior vena cava syndrome or spinal cord compression), vascular abnormalities (e.g., hyperleukocytosis, anemia, coagulopathy), and metabolic emergencies (e.g., tumor lysis syndrome). Common complications developing after completion of treatment include leukoencephalopathy and neurocognitive defects; cataract formation; cardiomyopathy and congestive heart failure; hepatic dysfunction, fibrosis, and cirrhosis; radiation enteritis; renal dysfunction or failure; scoliosis and short stature; hypothyroidism; gonadal dysfunction; graft-versus-host disease; and development of secondary malignancies. Physician awareness of these complications will permit more effective patient surveillance, which may afford patients the opportunity for earlier intervention in these situations and improved quality of life.

Atypical cutaneous lymphoproliferative disorder in patients with HIV infection.

BACKGROUND: An inflammatory pruritic eruption which is characterized histologically by CD8+, atypical lymphocytes has been described in human immunodeficiency virus (HIV)-infected patients. This disorder has been described as "pseudo-Sezary" or a "cutaneous T cell lymphoma (CTCL)-simulant", however, as these patients do not resemble CTCL clinically, and the relationship between this entity and CTCL is unclear, a more descriptive term is "atypical cutaneous lymphoproliferative disorder" (ACLD). The purpose of this study is to categorize the clinical, histologic, and immunophenotypic features of 16 HIV-infected patients with this skin disorder seen at the New York Department of Veterans Affairs Medical Center. METHODS: A retrospective chart review was conducted on 16 HIV-infected patients with a histologic diagnosis of an atypical cutaneous lymphoproliferative infiltrate on skin biopsy. Skin biopsies were reviewed, and histologic features noted. Immunophenotyping was performed on 14 out of 16 samples; electron microscopy was performed on samples from five patients. Clinical manifestations, disease course, medication history, and response to treatment were noted. RESULTS: The patients presented with a pruritic, persistent, generalized, papular eruption. Pigment changes, including hyperpigmentation and hypopigmentation were common. Histologically, lesional biopsies were characterized by a superficial and deep polymorphous infiltrate with atypical lymphocytes which were CD8+ predominant, Ki-1 negative, and occasionally CD7 antigen depleted. Sezary-like cells were present in the infiltrate in four out of five patients by electron microscopy. None of the patients has systemic manifestations of lymphoma; however, one of the 16 patients eventually developed frank CTCL. CONCLUSIONS: HIV-infected patients can present with a pruritic, widespread disorder, often with pigment changes characterized by an atypical cutaneous lymphocytic infiltrate. This clinicopathologic disorder is a rare, reactive inflammatory condition which generally occurs in late stage HIV infection and rarely progresses to frank lymphoma.

Perlman syndrome: a case report emphasizing its similarity to and distinction from Beckwith-Wiedemann and prune-belly syndromes.

Perlman syndrome is a rare entity characterized by hypotonia, facial dysmorphism, gigantism, and visceromegaly including nephromegaly. The current case illustrates the ultrasonographic and computed tomographic appearances of renal abnormalities in this condition. Findings in Perlman syndrome can overlap with and need to be distinguished from two more common clinical entities: prune-belly and Beckwith-Wiedemann syndromes. Additional cranial findings previously unreported are also described.

Magnetic resonance imaging of Takayasu's aortitis in an infant.

A fusiform aneurysm involving the ascending aorta and aortic arch in an 8-month-old infant was imaged with magnetic resonance. Histologic studies of the excised aneurysm indicated Takayasu's arteritis. Takayasu's arteritis has rarely been reported in infants, and involvement of the ascending aorta and aortic arch is an unusual finding in this age group.

Detection of Bartonella (Rochalimaea) henselae bacteremia using BacT/Alert blood culture system.

Bartonella henselae was isolated from the blood of five febrile immunosuppressed patients using BacT/Alert (Organon Teknika, Durham, NC) automated microbial detection system. An immunofluorescence assay (using 1:1000 dilutions) was used to confirm identification of fastidious, pleomorphic, non-Gram staining, argyrophilic bacilli displaying rachety motility that had been presumptively identified as Bartonella spp. The practicality of identification of Bartonella henselae using goat antisera for use in a routine clinical microbiology laboratory was demonstrated by this study.

Evaluation of new rapid commercial enzyme immunoassay for detection of Cryptosporidium oocysts in untreated stool specimens.

Sixty-six stool specimens were evaluated by the ProSpecTR Cryptosporidium rapid enzyme immunoassay (EIA) (Alexon, Sunnyvale, Calif.). Approximately 2 g of untreated stool suspended in buffer was filtered through membranes labelled with anti-Cryptosporidium-specific antigen antibody. Anti-Cryptosporidium-specific antigen antibody was labelled with biotin, horseradish peroxidase conjugated to streptavidin, and tetramethylbenzidine, and each labelled antibody was added in sequence to the membranes. Each membrane had a positive control and test area. EIA results were compared with those of the modified acid-fast procedure. Twenty-three specimens were positive by the initial acid-fast procedure and the EIA. Forty-two specimens were negative by the initial acid-fast test and the EIA. One specimen was negative by the initial acid-fast test and positive by the EIA (sensitivity, 100%; specificity, 98.5%). This technique is easy to use by comparison with the cumbersome, labor-intensive, and more subjective microscopic methods currently available, and its sensitivity equals that of current microscopic methods.

Pictorial review of the usual and unusual roentgen manifestations of childhood tuberculosis.

Despite advances in management of infectious diseases, tuberculosis remains a significant cause of morbidity and mortality in urban populations. In the pediatric age group, 65% of patients presenting with tuberculosis are asymptomatic. Recognition of the usual and unusual roentgen manifestations of this infectious disease often provides the only clue to the diagnosis.

Clinical utility of bone scan features of pleural effusion: sensitivity and specificity for malignancy based on pleural fluid cytopathology.

UNLABELLED: Asymmetric chest activity with malignant and benign pleural effusions has been described in bone scans. However, the clinical utility of this finding is not elucible from the literature. We developed specific scintigraphic criteria for malignant pleural effusion and retrospectively assessed their sensitivity and specificity in a group of patient scans. METHODS: Pleural fluid was submitted for cytopathology from 850 patients over a 5-yr period. Bone scans were done within 2 mo of the thoracentesis in 74 patients. As a consensus panel, we reread the scans and reviewed the cytology. RESULTS: The effusions were cytologically malignant in 25/74 patients (34%), indeterminate in 9/74 (12%) and benign in 40/74 (54%). Based on cytopathology, malignant pleural effusions were detected by bone scans with a sensitivity of 34%-50% and a specificity of 78%-89%; true sensitivity and specificity was somewhere in between averaging 42% (95% confidence interval 24%-60%) and 84% (95% confidence interval 73%-95%), respectively. CONCLUSIONS: The bone scan is frequently the first examination suggesting pleural metastasis, and when it is detected it should be pursued beyond pleural fluid cytology, if negative or indeterminate.

Optimized diagnostic strategy for neuroblastoma in opsoclonus-myoclonus.

Infantile myoclonic encephalopathy (opsoclonus-myoclonus or IME) is a rare clinical syndrome associated with occult neuroblastoma in 20%-50% of all cases. IME is the initial presentation of neuroblastoma in 1%-3% of children. Imaging approaches including chest radiography and abdominal computed tomography (CT) have been proposed to detect neuroblastoma in IME. Metaiodobenzylguanidine (MIBG) is highly effective in the detection of neuroblastoma. These scans can identify both soft-tissue and skeletal lesions anywhere in the body. Our purpose was to attempt to determine the best screening method for detection of occult neuroblastoma in patients with IME. Records of all neuroblastoma patients from 1983 to May 1991 were reviewed. Four cases of IME with neuroblastoma were identified in which imaging studies included an MIBG scan. All four patients had positive MIBG scans (100%) while only two had masses on initial CT (50%). In the three patients initially evaluated by traditional methods, the mean time to diagnosis and the mean number of advanced radiologic studies were 7.5 mo and 7.3 studies respectively. The patient screened with MIBG had only cranial and abdominal CT prior to surgery. Although based on a limited number of patients, results suggest that MIBG may prove to be a useful screening procedure in patients with IME. Traditional imaging modalities can then be directed to evaluate sites of disease identified by MIBG scans.

Gorham's disease involving the thoracic skeleton. Plain films and CT in two cases.

Two cases of Gorham's disease (massive osteolysis, idiopathic osteolysis, vanishing bone disease) involving the thoracic skeleton are reported. Both patients were adolescent females with involvement of multiple ribs. Involvement of the thoracic spine and pleural effusions--unusual manifestations carrying a poor prognosis--were also present. The radiographic and computed tomographic appearances are included with discussion and review of this disease entity.

Efficacy of metaiodobenzylguanidine as a scintigraphic agent for the detection of neuroblastoma.

RATIONALE AND OBJECTIVES: Metaiodobenzylguanidine (MIBG) has been shown to be both sensitive and highly specific for the detection of neuroblastoma. However, controversy surrounds its sensitivity in detecting neuroblastoma when compared with radionuclide (technetium 99m-methylene diphosphonate [99mTc]-MDP) bone scans. Because a diagnostic test ideally should be easy to interpret in addition to being sensitive and specific, this study aims to determine the most efficacious scintigraphic agent for diagnostic use in neuroblastoma. METHODS: Twenty patients with neuroblastoma had a total of 26 paired MIBG and 99mTc-MDP bone scans obtained less than 4 weeks apart. Each study was evaluated independently of its counterpart by six separate observers (3 experienced and 3 inexperienced in MIBG scintigraphy) to determine the presence or absence of disease and the tumor burden. RESULTS: Inexperienced observers reported more confidence in their interpretations of 99mTc-MDP bone scans; however, seven false-positive bone scans were reported. Using MIBG, all true-positive and true-negative scans, as well as significantly more sites of both primary and metastatic disease, were identified by all observers. CONCLUSION: This study suggests that MIBG is the more efficacious agent for the scintigraphic evaluation of neuroblastoma.

Neuroblastoma: dose-related sensitivity of MIBG scanning in detection.

Iodine-131 metaiodobenzylguanidine (MIBG) has shown effectiveness as a systemic radiotherapeutic agent in neuroblastoma. The authors postulated a likely dose-related relationship of MIBG sensitivity when it was administered for neuroblastoma detection. They studied this relationship in neuroblastoma patients who underwent scanning after receiving diagnostic and therapeutic doses of MIBG in temporal proximity. Seven patients with stage IV disease received a total of 14 therapeutic administrations of I-131 MIBG (150-350 mCi [5,550-12,950 MBq]/m2 per treatment). Posttherapy scans were obtained at 3 and at 5-7 days. Diagnostic MIBG scans had been obtained no more than 4 weeks before the start of therapy. Use of diagnostic MIBG scanning led to underestimation of the tumor burden by 50% compared with use of posttherapy scanning. This difference may be an important consideration in selecting therapeutic strategies for individual patients. It further suggests that use of much larger diagnostic doses of MIBG is a rational strategy in histologically confirmed cases of advanced disease.